The long term objectives of this proposal are to improve our management of symptomatic hemangiomas of infancy (HOI) and to advance our understanding of this common, and sometimes life-threatening, vascular anomaly through a clinically and molecular based investigation. Hemangiomas are the most common pediatric neoplasm affecting 10% of infants. Despite their anticipated course of natural involution, medical intervention is indicated in 10-25% of patients to treat significant symptoms or to prevent serious sequelae. HOI warranting therapy are most frequently treated with corticosteroids but clinical response is unpredictable and side effects to this class of medications are common. A recent report highlighting propranolol as an alternative treatment of HOI has sparked much enthusiasm. Although intriguing, the use of propranolol for HOI has neither been verified nor studied. The specific clinical aims of this study are: 1. to assess the feasibility of conducting a prospective, randomized, physician-blinded, multi-institutional study to evaluate propranolol versus prednisolone, the comparative control, in treating HOI and to assess the failure rate of each medication at one month. 2. to assess the outcome of both treatments in terms of monthly comprehensive evaluations completed by a physician blinded to treatment arm, changes in somatic growth and changes in lesion volume measured on pre and post imaging studies using innovative Voxar 3D volumetric averaging software. 3. to assess tolerability of each treatment through monthly parental quality of life inventories, changes in somatic growth and comprehensive evaluations completed by a physician blinded to treatment arm. This proposal will also analyze the biology of HOI on molecular level. Proteomic and metabolomic analysis of urine collected from participants before, during and after treatment will be analyzed to identify predictors of clinical response to therapy. Additionally, hemangioma tissue excised for diagnostic purposes will be studied by microarray gene analysis to identify candidate genes and RNA that correlate with disease extent or that predict response to therapy. Data derived from this feasibility study will be used to determine if a more powerful study is indicated to compare these two treatments and to better elucidate the molecular mechanisms behind this neoplasm's progression, guiding further research into novel molecular biomarkers and potential therapeutic targets. PUBLIC HEALTH RELEVANCE: This study compares the effect and side effects of two different medicines used to treat hemangiomas, which are common benign blood vessel tumors that occur in infants. Studies of the genetic make-up of cells from hemangiomas are also proposed to improve our understanding of this congenital anomaly.